Support data scaling (chds) parameter

This sounds like exactly what I need and what many users would also need - I'm puzzled as to why it wasn't in place anyway surely any user will need what you describe before long?

Anyway, I have made all the additions to my local version of the chart module as per your instructions but can't get it working. Here's the details.

What I want is for my line chart (comprising two data sets) to scale its actual data values (which range from between roughly 80 and 100) so that they 'fill' the whole of the vertical available space.

In order to achieve this, am I correct in thinking that the following will do the job...

I set up an array which I called data_scalers to hold the min and max values for the two series.

/* Data scaling */
$data_scalers = array();
$data_scalers[] = 80;
$data_scalers[] = 100;
$data_scalers[] = 80;
$data_scalers[] = 100;

So that the data_scalers array is filled {80,100,80,100} to accomodate both data sets.

I then followed this with ...

'#data_scale' => $data_scalers

... as the last line of the '$chart = array(.....) bit inside the brackets of course.

The only reference 'chds' that I can see in the output URI is as follows...

...&chxt=y%2Cy%2Cx&chds=%2Cchd=t%3A87.912777500%2C...

Any guidance?

Thanks

Nick

@SirClickaLot, and anyone else who wants to use this with multiple series...

you'll need to add extra array elements in the functions.

eg, for xy charts, change the code snippets like this:

<?php
   case 'chds':
      $data[$attr] .= implode(',', array($value['#minx'], $value['#maxx'], $value['#miny'], $value['#maxy']));
      break;
?>

<?php
function chart_data_scale($miny = 1, $maxy = 100, $minx = 1, $maxx = 100) {
  return array(       
      '#miny'    => $miny,  
      '#maxy' => $maxy, 
      '#minx'    => $minx,  
      '#maxx' => $maxx, 	  
    );
}
?>

And pass the values in like this:

<?php
$chart = array(
      '#chart_id' => 'test_chart',
      '#title' => t('My test'),
      '#type' => CHART_TYPE_GMETER,
    );
$chart['#data_scale'] = array(
    '#minx'=> 354,
    '#maxx'=> 872,
    '#miny'=> 0,
    '#maxy'=> 10000);

$chart['#data']['test'] = 0;
$chart['#labels'][] = t('Test Label');

  echo chart_render($chart);
?>

Handles multiple ranges as per @ppcc's comment above, which I haven't tested extensively.

Rerolled against current HEAD, previous patch was no longer applying.

Thanks for the patch, folks. Works for me, too.

But the module status is "Minimally maintained" and "Maintenance fixes only". Rather than piecemeal patches of this sort, if anyone has any thoughts on #1109472: Hook chart_post_build to append custom GIC parms (to be commented on in that thread, not this one), maybe we could encourage another more encompassing, future-proof release?

I think the following would be a better solution since you can have multiple series (more than just 2 like the previous patch handled):

    // Bar chart data scaling
    case 'chds':
      if (count($value) && isset($value['#max'])) {
        $data[$attr] = implode(',', $value);
      }
      elseif (count($value)) {
        $scales = array();
        foreach($value AS $i => $scale){
          $scales[] = implode(',', $scale);
        }
        $data[$attr] = implode(',', $scales);
      }
      break;

function chart_data_scale($min = 1, $max = 100) {
  return array(
      '#min' => $min,
      '#max' => $max,
    );
}

Usage:

$chart['#data_scale'][] = chart_data_scale(0, 10);

With the patch I posted at #1109472: Hook chart_post_build to append custom GIC parms you can use a new hook to implement more API parameters.

Many thanks to grobot
This patch works great! However, it is somehow disappointing because it is still not released.
Regards, Tilo

I'm stuck on a large project, I'll be working on this issue queue again as soon as I am done.

Trying to get this issue moving again, refer to the parent link I added for details.

I am closing this issue, as Drupal 6 is no longer supported.